Terraria and More Tools (version 0.8.0-0.9.0)

Features:

Lapis Tools/Armor

Redstone Tools/Armor

Emerald Tools/Armor

Key Holder Boss

Emerald Bow

Demon Eyes (three types)

Green Slimes

Lens 

Gel

Eye of Cthulu

Legendary Bow

Cobalt Tools/Armor

Palladium Tools/Armor

Mythril Tools/Armor

Orichalcum Tools/Armor

Excalibur (different recipe)

Titanium Sword

Adamantite Sword

Adamantite Axe

Special Sticks

Night's Edge

Better Chests (obsidian chests)

6 non-terraria regular mobs

Legend Key/Shard/Nugget

Mythril/Orichalcum and Cobalt/Palladium Nuggets

Sharp Swords (creative only)

Terra Beam (creative only)

Note: These features are for the newest version, not all versions

I suggest NEI of JEI for the crafting recipes, as there are lots. Click on an unopened door with a diamond sword to spawn the key holder boss. It drops a legend key, a vital ingredient for emerald+ tools.

These emerald tools are special, and use grass sticks (2 sticks, 2 seeds and legend shard makes 4) instead of regular. They are stronger than diamond.

Emerald boots are the best boots added in the mod, and get rid of fall damage. Emerald armor is crafted with a legend nugget. (9th of legend shard, 81st of legend key)